A scientist's aim in a discussion with his colleagues is not to persuade, but to clarify.

I have been asked whether I would agree that the tragedy of the scientist is that he is able to bring about great advances in our knowledge, which mankind may then proceed to use for purposes of destruction. My answer is that this is not the tragedy of the scientist; it is the tragedy of mankind.

Don't lie if you don't have to.

When a scientist says something, his colleagues must ask themselves only whether it is true. When a politician says something, his colleagues must first of all ask, 'Why does he say it?

A great power imposes the obligation of exercising restraint, and we did not live up to this obligation. I think this affected many of the scientists in a subtle sense, and it diminished their desire to continue to work on the bomb.

I am thinking of keeping a diary, not with the intend to publish it, merely to record the facts for the information of God, in case God does not know my version of the facts.

Those individuals who give moral considerations a much greater weight than considerations of expediency represent a comparatively small minority, five percent of the people perhaps. But, In spite of their numerical inferiority, they play a major role in our society because theirs is the voice of the conscience of society.